Scalp treatment

ABSTRACT

A composition for topical application to the scalp comprises (i) an anti-dandruff agent; (ii) conjugated linoleic acid; and (iii) a cosmetically acceptable diluent or carrier.

The present invention relates to compositions for topical application tothe scalp, methods of treating and/or preventing dandruff and scalp itchand the use of a synergistic combination of components in themanufacture of a composition for treating and/or preventing dandruff andscalp itch.

It is widely believed that Malassezia yeasts, such as Malassezia furfur,are the main cause of dandruff. However, it is unclear why some peoplesuffer from this condition while others do not. What is known is thatincreasing the level of Malassezia on the scalp does not automaticallylead to dandruff. This suggests that Malassezia is necessary but notsufficient to cause the condition.

The main, if not only, intervention strategy used on the marketcurrently for the treatment of dandruff is the topical application ofantifungals such as zinc pyrithione (ZnPTO), octopirox and ketoconazolewhich are normally delivered from a shampoo. These antifungal agentsremove (or at least reduce the level of) the Malassezia from the scalp,and provide effective treatment of the dandruff condition. In some casesthe anti-fungal activity of these actives is complemented by theaddition of a secondary active such as salicylic acid which acts as akeratolytic.

However, although clinically proven to be effective in treating theclinical symptoms of dandruff over a 2-4 week period, knownanti-dandruff compositions may be less effective in treating the keyconsumer symptoms of dandruff rapidly and effectively. The main globalconsumer symptoms of dandruff are visible skin flakes in hair and onshoulders and scalp itch. Of the two symptoms, scalp itch may be themore significant symptom of dandruff.

Conjugated linoleic acid (CLA) comprises a mixture of positional andgeometric isomers of octadecadienoic acid in which the two double bondshave a conjugated configuration. Natural CLA is produced by bacteriapresent in the rumen and can therefore be found in meat and dairyproducts derived from ruminants.

A number of potential health benefits have been associated with CLA.Increasing evidence exists for its effects on reducing body fat(Blankson et al. 2000, Mougios et al. 2001, Smedman et al. 2001) and itsimmunomodulatory effects in humans (Albers et al. 2001).

Furthermore, CLA has anti-carcinogenic and anti-inflammatory propertiesand reduces the risk of cardiovascular diseases. Loders Croklaan LipidNutrition produces CLA from safflower oil resulting in a 1:1 mixture ofcis-9,trans-11 and trans-10,cis-12 isomer of CLA. This mixture ismarketed in free fatty acid form (Clarinol™ A) as well as intriacylglycerol-form (Clarinol™ G).

WO 00/37040 teaches skin care compositions enriched in cis-9, trans-11linoleic acid or derivatives thereof. The compositions are useful forthe treatment and/or prevention of normal skin conditions due to ageingor chronoaging, such as wrinkles, lines, sagging, hyperpigmentation andage spots, and/or of sensitive, dry, rough, flaky, red, itchy andirritated skin.

WO 01/79241 discloses specific glycoside esters of fatty acids, such asconjugated linoleic acids, and a method for their preparation. WO01/79241 speculates that the compounds may be useful in a broad range ofpossible applications including cosmetics, pharmaceuticals, foodsupplements and animal feeds. In particular, WO 01/79241 teaches thatglycoside esters of conjugated linoleic acid may prevent fat build up.

WO 02/09664 describes cosmetic or dermatological compositions comprisingcombinations of bioquinones, potassium channel openers and/or5-alpha-reductase inhibitors. The compositions are said to be useful forprolonging the anagenic phase and/or for the treatment and prophylaxisof seborrhoeic symptoms. Conjugated fatty acids may optionally bepresent in the compositions.

EP 0116439 discloses hair tonic compositions which include fatty acids,such as petroselinic acid, linoleic acid, linolenic acid, oleic acid andarachidonic acid for alleviating dandruff and for stimulating hairgrowth. There is no mention in this document of conjugated linoleicacid.

There remains a need for topical compositions which are effective forboth the treatment and/or prevention of dandruff and scalp itch.

Accordingly, in a first aspect, the present invention provides acomposition for topical application to the scalp comprising

-   -   (i) an anti-dandruff agent;    -   (ii) conjugated linoleic acid; and    -   (iii) a cosmetically acceptable diluent or carrier.

A second aspect of the invention is a system for treating dandruffcomprising: a first component comprising an anti-dandruff agent; and asecond component comprising conjugated linoleic acid, wherein said firstcomponent and said second component are for topical application to thescalp and are in separate compartments within said system.

In another aspect, the present invention provides a method of treatingand/or preventing dandruff which comprises applying to the scalp acomposition or system of the invention.

In a further aspect, the present invention relates to the use of asynergistic combination of an anti-dandruff agent and conjugatedlinoleic acid in the manufacture of a composition for treating and/orpreventing dandruff.

In a yet further aspect, the present invention relates to a method oftreating and/or preventing scalp itch which comprises applying to thescalp a composition or system of the invention.

In a still further aspect, the present invention relates to the use of asynergistic combination of an anti-dandruff agent and conjugatedlinoleic acid in the manufacture of a composition for treating and/orpreventing scalp itch.

Anti-dandruff agents may be used alone or as mixtures of one or moresuch agents. Suitable examples of anti-dandruff agents includeanti-fungal agents such as the heavy metal salts of pyridinethione(pyrithione), especially zinc pyridinethione, and other antimicrobialssuch as selenium sulphide. The anti-dandruff agents may be soluble,partially soluble or insoluble in the compositions of the invention.

The anti-fungal agents typically display a minimum inhibitoryconcentration of about 50 mg/ml or less against Malassezia.

In a preferred embodiment of the present invention, the anti-dandruffagent is selected from metal pyrithiones, climbazole, ketoconazole andoctopirox.

Preferably, the antidandruff agent comprises an optionally substitutedimidazolyl group, more preferably an unsubstituted imidazolyl groupand/or a phenyl group substituted with one or two chloro substituents.Examples of such anti-dandruff agents include ketoconazole andclimbazole.

A particularly preferred antifungal agent is zinc pyrithione (ZnPTO)which, on account of its relative insolubility in aqueous systems, isgenerally used in hair treatment compositions as a particulatedispersion. The zinc pyrithione may be used in any particle formincluding, for example, crystalline forms such as platelets and needlesand amorphous, regularly or irregularly shaped particles.

If zinc pyrithione is present in the composition, a suspending agent ispreferably used to prevent or inhibit the settling of the particles outof the composition. The average particle diameter of the zinc pyrithioneparticles (ie, their maximum dimension) is typically from about 0.2 toabout 50 μm, preferably from about 0.4 to about 10 μm, such as about 0.1to about 5 μm, more preferably from 0.1 μm to 1 μm as determined, forexample, using a Malvern Mastersizer (Malvern Instruments, UK).

The anti-dandruff agent is preferably present in the compositions of theinvention in an amount of from about 0.01% to about 10.0% by weight,more preferably from about 0.1% to about 5.0% by weight, even morepreferably from about 0.1% to about 1.0% by weight, such as from about0.2% to about 0.8% by weight eg, about 0.5% by weight.

Conjugated linoleic acid (hereinafter referred to as CLA) is adi-unsaturated long chain (C18) fatty acid. CLA comprises a group ofpositional and geometric isomers of linoleic acid in which variousconfigurations of cis and trans double bonds at positions (6, 8), (7,9), (8, 10), (9, 11), (10, 12) or (11, 13) are possible. Thus,twenty-four different isomers of CLA exist. The compositions of theinvention may comprise any of these isomers, either alone or in anycombination.

In the invention the term “conjugated linoleic acid” also includesderivatives of the free acid which thus comprise conjugated linoleicacid moieties.

Preferable derivatives include those derived from substitution of thecarboxyl group of the acid, such as esters (e.g. triglyceride esters,monoglyceride esters, diglyceride esters, phosphoesters), amides (e.g.ceramide derivatives), salts (e.g. alkali metal and alkali earth metalsalts, ammonium salts); and/or those derived from substitution of theC18 carbon chain, such as alpha hydroxy and/or beta hydroxy derivatives.Preferably, where the derivative of CLA is an ester, it is not aglycoside.

In the case of triglyceride ester derivatives, all positional isomers ofCLA substituents on the glycerol backbone are included. Thetriglycerides must contain at least one CLA moiety. For example, of thethree esterifiable positions on the glycerol backbone, the 1 and 2positions may be esterified with CLA and by another lipid at position 3or as an alternative, the glycerol backbone could be esterified by CLAat the 1 and 3 positions with another lipid at position 2.

The most preferred isomers of CLA for use in the present invention arethe cis 9 trans 11 (c9 t11) or trans 10 cis 12 (t10 c12) isomer.Preferably at least 1% by weight of the total CLA and/or CLA moietiespresent in the composition is in the form of the c9, t11 and/or t10, c12isomer. More preferably at least 20% and most preferably at least 40%,by weight of the total CLA and/or CLA moieties present in thecomposition, is in the form of the c9, t11 isomer and/or t10, c12isomer.

In a particularly preferred embodiment the conjugated linoleic acid isenriched in the c9 t11 or the t10, c12 isomer. By “enriched” it is meantthat at least 50% by weight of the total CLA (and/or CLA) moietiespresent in the composition is in the form of the cis 9, trans 11 or thetrans 10 cis 12 isomer. Preferably, at least 70%, more preferably atleast 80%, and most preferably at least 90% by weight of the total CLAand/or CLA moieties present in the composition, are in the form of thec9, t11 isomer or the t10 c12 isomer.

The CLA and/or derivatives thereof comprising CLA moieties according tothe present invention are commercially available as oils that are richin conjugated linoleic acid triglyceride such as Tung oil or asdehydrated castor oil (Unichema). A mixed isomer product is availablefrom Sigma and a c9 t11 isomer enriched CLA is available from Matreyainc.

Alternatively, CLA according to the preferred embodiments of the presentinvention may be prepared according to the method disclosed in WO97/18320 whose contents are incorporated herein by reference.

Wherever the term “conjugated linoleic acid” or “CLA” is used in thisspecification it is to be understood that the derivatives thereofcomprising CLA moieties are also included. “CLA moieties” refers to CLAfatty acyl portion(s) of a CLA derivative.

The CLA to be employed in accordance with the present invention ispresent in the topical composition in an effective amount. Typically,CLA is present in an amount of from 0.0001% to 20% by weight of thetotal composition. Preferably the amount of CLA is from 0.001% to 5%,more preferably from 0.001 to 2% and most preferably from 0.01% to 1% byweight of the total composition.

The composition according to the invention comprises a cosmeticallyacceptable diluent or carrier to act as a vehicle for the anti-dandruffagent and conjugated linoleic acid. The diluent or carrier may comprisematerials commonly employed in hair care products such as water, liquidemollients, silicone oils, emulsifiers, solvents such as, for example,ethanol and propanol, humectants, thickeners, powders, propellants andthe like.

The diluent or carrier may be present in an amount of from 0.1% to 99%by weight, more preferably from 1.0% to 98% by weight of the totalcomposition. It is particularly preferred if the diluent or carrier ispresent in an amount of from 15% to 96% by weight, most preferably from25% to 95% by weight of the total composition.

Compositions of the invention typically also comprise a perfume orfragrance.

It is particularly preferred if the composition according to the presentinvention is a shampoo.

Such shampoo compositions will typically contain water in an amount offrom about 50% to about 98% by weight, preferably from about 60% toabout 90% by weight, most preferably at least 70% by weight.

A shampoo composition of the invention will also comprise one or morecleansing surfactants that are cosmetically acceptable and suitable fortopical application to the hair. Further surfactants may be present asan additional ingredient if sufficient for cleansing purposes is notprovided as emulsifier for any emulsified components in the composition,e.g. emulsified silicones. It is preferred that shampoo compositions ofthe invention comprise at least one further surfactant (in addition tothat used as emulsifying agent) to provide a cleansing benefit.

Suitable cleansing surfactants, which may be used singularly or incombination, are selected from anionic, amphoteric and zwitterionicsurfactants, and mixtures thereof. The cleansing surfactant may be thesame surfactant as the emulsifier, or may be different.

Examples of anionic surfactants are the alkyl sulphates, alkyl ethersulphates, alkaryl sulphonates, alkanoyl isethionates, alkyl succinates,alkyl sulphosuccinates, N-alkyl sarcosinates, alkyl phosphates, alkylether phosphates, alkyl ether carboxylates, and alpha-olefinsulphonates, especially their sodium, magnesium, ammonium and mono-, di-and triethanolamine salts. The alkyl and acyl groups generally containfrom 8 to 18 carbon atoms and may be unsaturated. The alkyl ethersulphates, alkyl ether phosphates and alkyl ether carboxylates maycontain from 1 to 10 ethylene oxide or propylene oxide units permolecule.

Typical anionic surfactants for use in shampoos of the invention includesodium oleyl succinate, ammonium lauryl sulphosuccinate, ammonium laurylsulphate, sodium dodecylbenzene sulphonate, triethanolaminedodecylbenzene sulphonate, sodium cocoyl isethionate, sodium laurylisethionate and sodium N-lauryl sarcosinate. The most preferred anionicsurfactants are sodium lauryl sulphate, triethanolamine monolaurylphosphate, sodium lauryl ether sulphate 1 EO, 2EO and 3EO, ammoniumlauryl sulphate and ammonium lauryl ether sulphate 1EO, 2EO and 3EO.

Examples of amphoteric and zwitterionic surfactants include alkyl amineoxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines(sultaines), alkyl glycinates, alkyl carboxyglycinates, alkylamphopropionates, alkylamphoglycinates, alkyl amidopropylhydroxysultaines, acyl taurates and acyl glutamates, wherein the alkyland acyl groups have from 8 to 19 carbon atoms. Typical amphoteric andzwitterionic surfactants for use in shampoos of the invention includelauryl amine oxide, cocodimethyl sulphopropyl betaine and preferablylauryl betaine, cocamidopropyl betaine and sodium cocamphopropionate.

The shampoo composition can also include co-surfactants, to help impartaesthetic, physical or cleansing properties to the composition. Apreferred example is a nonionic surfactant, which can be included in anamount ranging from 0% to about 5% by weight of the total composition.

For example, representative nonionic surfactants that can be included inshampoo compositions of the invention include condensation products ofaliphatic (C₈-C₁₈) primary or secondary linear or branched chainalcohols or phenols with alkylene oxides, usually ethylene oxide andgenerally having from 6 to 30 ethylene oxide groups.

Other representative nonionics include mono- or di-alkyl alkanolamides.Examples include coco mono- or di-ethanolamide and cocomono-isopropanolamide.

Further nonionic surfactants which can be included in shampoocompositions of the invention are the alkyl polyglycosides (APGs).Typically, the APG is one which comprises an alkyl group connected(optionally via a bridging group) to a block of one or more glycosylgroups. Preferred APGs are defined by the following formula:RO-(G)_(n)wherein R is a branched or straight chain alkyl group which may besaturated or unsaturated and G is a saccharide group.

R may represent a mean alkyl chain length of from about C₅ to about C₂₀.Preferably R represents a mean alkyl chain length of from about C₈ toabout C₁₂. Most preferably the value of R lies between about 9.5 andabout 10.5. G may be selected from C₅ or C₆ monosaccharide residues, andis preferably a glucoside. G may be selected from the group comprisingglucose, xylose, lactose, fructose, mannose and derivatives thereof.Preferably G is glucose.

The degree of polymerisation, n, may have a value of from about 1 toabout 10 or more. Preferably, the value of n lies in the range of fromabout 1.1 to about 2. Most preferably the value of n lies in the rangeof from about 1.3 to about 1.5.

Suitable alkyl polyglycosides for use in the invention are commerciallyavailable and include for example those materials identified as: OramixNS10 ex Seppic; Plantaren 1200 and Plantaren 2000 ex Henkel.

The total amount of surfactant (including any co-surfactant, and/or anyemulsifier) in shampoo compositions of the invention is generally from0.1 to 50% by weight, preferably from 5 to 30%, more preferably from 10%to 25% by weight of the total shampoo composition.

A cationic deposition polymer is a preferred ingredient in shampoocompositions of the invention, for enhancing conditioning performance ofthe shampoo. By “deposition polymer” is meant an agent which enhancesdeposition of one or more insoluble components from the shampoocomposition onto the intended site during use, i.e. the hair and/or thescalp.

The deposition polymer may be a homopolymer or be formed from two ormore types of monomers. The molecular weight of the polymer (in g/mol)will generally be between 5 000 and 10 000 000, typically at least 10000 and preferably in the range 100 000 to about 2 000 000. The polymerswill have cationic nitrogen containing groups such as quaternaryammonium or protonated amino groups, or a mixture thereof.

The cationic nitrogen-containing group will generally be present as asubstituent on a fraction of the total monomer units of the depositionpolymer. Thus when the polymer is not a homopolymer it can containspacer non-cationic monomer units. Such polymers are described in theCTFA Cosmetic Ingredient Directory, 3rd edition. The ratio of thecationic to non-cationic monomer units is selected to give a polymerhaving a cationic charge density in the required range.

Suitable cationic deposition polymers include, for example, copolymersof vinyl monomers having cationic amine or quaternary ammoniumfunctionalities with water soluble spacer monomers such as(meth)acrylamide, alkyl and dialkyl (meth)acrylamides, alkyl(meth)acrylate, vinyl caprolactone and vinyl pyrrolidine. The alkyl anddialkyl substituted monomers preferably have C1-C7 alkyl groups, morepreferably C1-3 alkyl groups. Other suitable spacers include vinylesters, vinyl alcohol, maleic anhydride, propylene glycol and ethyleneglycol.

The cationic amines can be primary, secondary or tertiary amines,depending upon the particular species and the pH of the composition. Ingeneral secondary and tertiary amines, especially tertiary, arepreferred.

Amine substituted vinyl monomers and amines can be polymerized in theamine form and then converted to ammonium by quaternization.

The cationic deposition polymers can comprise mixtures of monomer unitsderived from amine- and/or quaternary ammonium-substituted monomerand/or compatible spacer monomers.

Suitable cationic deposition polymers include, for example:

copolymers of 1-vinyl-2-pyrrolidine and 1-vinyl-3-methyl-imidazoliumsalt (e.g. chloride salt), referred to in the industry by the Cosmetic,Toiletry, and Fragrance Association, (CTFA) as Polyquaternium-16. Thismaterial is commercially available from BASF Wyandotte Corp.(Parsippany, N.J., USA) under the LUVIQUAT tradename (e.g. LUVIQUAT FC370);

copolymers of 1-vinyl-2-pyrrolidine and dimethylaminoethyl methacrylate,referred to in the industry (CTFA) as Polyquaternium-11. This materialis available commercially from Gaf Corporation (Wayne, N.J., USA) underthe GAFQUAT tradename (e.g., GAFQUAT 755N);

cationic diallyl quaternary ammonium-containing polymers including, forexample, dimethyldiallyammonium chloride homopolymer and copolymers ofacrylamide and dimethyldiallylammonium chloride, referred to in theindustry (CTFA) as Polyquaternium 6 and Polyquaternium 7, respectively;

mineral acid salts of amino-alkyl esters of homo-and co-polymers ofunsaturated carboxylic acids having from 3 to 5 carbon atoms, (asdescribed in U.S. Pat. No. 4,009,256);

cationic polyacrylamides(as described in WO95/22311).

Other cationic deposition polymers that can be used include cationicpolysaccharide polymers, such as cationic cellulose derivatives,cationic starch derivatives, and cationic guar gum derivatives.

Cationic polysaccharide polymers suitable for use in compositions of theinvention include those of the formula:A-O—[R—N⁺(R¹)(R²)(R³)X⁻],wherein: A is an anhydroglucose residual group, such as a starch orcellulose anhydroglucose residual. R is an alkylene, oxyalkylene,polyoxyalkylene, or hydroxyalkylene group, or combination thereof. R¹,R² and R³ independently represent alkyl, aryl, alkylaryl, arylalkyl,alkoxyalkyl, or alkoxyaryl groups, each group containing up to about 18carbon atoms. The total number of carbon atoms for each cationic moiety(i.e., the sum of carbon atoms in R¹, R² and R³) is preferably about 20or less, and X is an anionic counterion.

Cationic cellulose is available from Amerchol Corp. (Edison, N.J., USA)in their Polymer JR (trade mark) and LR (trade mark) series of polymers,as salts of hydroxyethyl cellulose reacted with trimethyl ammoniumsubstituted epoxide, referred to in the industry (CTFA) asPolyquaternium 10. Another type of cationic cellulose includes thepolymeric quaternary ammonium salts of hydroxyethyl cellulose reactedwith lauryl dimethyl ammonium-substituted epoxide, referred to in theindustry (CTFA) as Polyquaternium 24. These materials are available fromAmerchol Corp. (Edison, N.J., USA) under the tradename Polymer LM-200.

Other suitable cationic polysaccharide polymers include quaternarynitrogen-containing cellulose ethers (e.g. as described in U.S. Pat. No.3,962,418), and copolymers of etherified cellulose and starch (e.g. asdescribed in U.S. Pat. No. 3,958,581).

A particularly suitable type of cationic polysaccharide polymer that canbe used is a cationic guar gum derivative, such as guarhydroxypropyltrimonium chloride (Commercially available from Rhodia(formerly Rhone-Poulenc) in their JAGUAR trademark series).

Examples are JAGUAR C13S, which has a low degree of substitution of thecationic groups and high viscosity. JAGUAR C15, having a moderate degreeof substitution and a low viscosity, JAGUAR C17 (high degree ofsubstitution, high viscosity), JAGUAR C16, which is a hydroxypropylatedcationic guar derivative containing a low level of substituent groups aswell as cationic quaternary ammonium groups, and JAGUAR 162 which is ahigh transparency, medium viscosity guar having a low degree ofsubstitution.

Preferably the cationic deposition polymer is selected from cationiccellulose and cationic guar derivatives. Particularly preferreddeposition polymers are JAGUAR C13S, JAGUAR C15, JAGUAR C17 and JAGUARC16 and JAGUAR C162.

The cationic deposition polymer will generally be present at levels offrom 0.001 to 5%, preferably from about 0.01 to 1%, more preferably fromabout 0.02% to about 0.5% by weight of the total composition.

The compositions of the invention may comprise solid active agents.Suitable solid active agents include pigment particles, such as soliddyes or colorants suitable for application to hair, and metal colloids.

Hair treatment compositions such as shampoos and conditioners arefrequently opacified or pearlised to enhance consumer appeal.

Examples of opacifying agents include higher fatty alcohols (e.g. cetyl,stearyl, arachidyl and behenyl), solid esters (e.g. cetyl palmitate,glyceryl laurate, stearamide MEA-stearate), high molecular weight fattyamides and alkanolamides and various fatty acid derivatives such aspropylene glycol and polyethylene glycol esters. Inorganic materialsused to opacify hair treatment compositions include magnesium aluminiumsilicate, zinc oxide, and titanium dioxide.

Pearlescing agents typically form thin, platelet-type crystals in thecomposition, which act like tiny mirrors. This gives the pearl lustreeffect. Some of the opacifying agents listed above may also crystalliseas pearlescing agents, depending on the media in which they are used andthe conditions employed.

Typical pearlescing agents may be selected from C16-C22 fatty acids(e.g. stearic acid, myristic acid, oleic acid and behenic acid), estersof C16-C22 fatty acid with alcohols and esters of C16-C22 fatty acidincorporating such elements as alkylene glycol units. Suitable alkyleneglycol units may include ethylene glycol and propylene glycol. However,higher alkylene chain length glycols may be employed. Suitable higheralkylene chain length glycols include polyethylene glycol andpolypropylene glycol.

Examples are polyethylene glycol mono or diesters of C16-C22 fatty acidshaving from 1 to 7 ethylene oxide units, and ethylene glycol esters ofC16-C22 fatty acids. Preferred esters include polyethylene glycoldistearates and ethylene glycol distearates. Examples of a polyethyleneglycol distearate available commercially are EUPERLAN PK900 (ex Henkel)or GENAPOL TS (ex Hoechst). An example of an ethylene glycol distearateis EUPERLAN PK3000 (ex Henkel).

Other pearlescing agents include alkanolamides of fatty acids havingfrom 16 to 22 carbon atoms, (e.g. stearic monoethanolamide, stearicdiethanolamide, stearic monoisopropanolamide and stearicmonoethanolamide stearate); long chain esters of long chain fatty acids(e.g. stearyl stearate, cetyl palmitate); glyceryl esters (e.g. glyceryldistearate), long chain esters of long chain alkanolamides (e.g.stearamide DEA distearate, stearamide MEA stearate), and alkyl (C18-C22)dimethyl amine oxides (e.g. stearyl dimethyl amine oxide).

Further suitable pearlescing agents include inorganic materials such asnacreous pigments based on the natural mineral mica. An example istitanium dioxide coated mica. Particles of this material may vary insize from 2 to 150 microns in diameter. In general, smaller particlesgive rise to a pearly appearance, whereas particles having a largeraverage diameter will result in a glittery composition.

Suitable titanium dioxide coated mica particles are those sold under thetrade names TIMIRON (merck) or FLAMENCO (Mearl).

The level of opacifying or pearlescing agent employed in compositions ofthe invention is generally from 0.01 to 20%, preferably 0.01 to 5%, morepreferably from 0.02 to 2% by weight of the total composition.

Gas (e.g. air) bubbles represent another type of suspended phase thatmay be introduced into a hair treatment composition for aestheticpurposes. When evenly sized and homogeneously dispersed in thecomposition, these can enhance consumer appeal.

Compositions in accordance with the invention may also be formulated asconditioners for the treatment of hair (typically after shampooing) andsubsequent rinsing.

Such a conditioner will comprise one or more conditioning surfactantswhich are cosmetically acceptable and suitable for topical applicationto the hair.

Suitable conditioning surfactants are selected from cationicsurfactants, used singly or in admixture. Examples include quaternaryammonium hydroxides or salts thereof, e.g. chlorides.

Suitable cationic surfactants for use in hair conditioners of theinvention include cetyltrimethylammonium chloride,behenyltrimethylammonium chloride, cetylpyridinium chloride,tetramethylammonium chloride, tetraethylammonium chloride,octyltrimethylammonium chloride, dodecyltrimethylammonium chloride,hexadecyltrimethylammonium chloride, octyldimethylbenzylammoniumchloride, decyldimethylbenzylammonium chloride,stearyldimethylbenzylammonium chloride, didodecyldimethylammoniumchloride, dioctadecyldimethylammonium chloride, tallowtrimethylammoniumchloride, cocotrimethylammonium chloride, and the correspondinghydroxides thereof. Further suitable cationic surfactants include thosematerials having the CTFA designations Quaternium-5, Quaternium-31 andQuaternium-18. Mixtures of any of the foregoing materials may also besuitable. A particularly useful cationic surfactant for use in hairconditioners of the invention is cetyltrimethylammonium chloride,available commercially, for example as GENAMIN CTAC, ex HoechstCelanese.

In conditioners of the invention, the level of cationic surfactant ispreferably from 0.01 to 10%, more preferably 0.05 to 5%, most preferably0.1 to 2% by weight of the composition.

Conditioners of the invention advantageously incorporate a fattyalcohol. The combined use of fatty alcohols and cationic surfactants inconditioning compositions is believed to be especially advantageous,because this leads to the formation of a lamellar phase, in which thecationic surfactant is dispersed.

Representative fatty alcohols comprise from 8 to 22 carbon atoms, morepreferably 16 to 20. Examples of suitable fatty alcohols include cetylalcohol, stearyl alcohol and mixtures thereof. The use of thesematerials is also advantageous in that they contribute to the overallconditioning properties of compositions of the invention.

The level of fatty alcohol in conditioners of the invention isconveniently from 0.01 to 10%, preferably from 0.1 to 5% by weight ofthe composition. The weight ratio of cationic surfactant to fattyalcohol is suitably from 10:1 to 1:10, preferably from 4:1 to 1:8,optimally from 1:1 to 1:4.

The compositions of the invention may comprise one or more conditioningagents. As used herein, the term “conditioning agent” includes anymaterial that is used to give a particular conditioning benefit to hairand/or skin. For example, in compositions for use in washing hair, suchas shampoos and conditioners, suitable materials are those which deliverone or more benefits relating to shine, softness, combability,wet-handling, anti-static properties, protection against damage, body,volume, stylability and manageability.

Preferred conditioning agents for use in the present invention includeemulsified silicones, used to impart for example wet and dryconditioning benefits to hair such as softness, smooth feel and ease ofcombability.

Various methods of making emulsions of particles of silicones for use inthe invention are available and are well known and documented in theart.

The viscosity of the silicone itself (not the emulsion or the finalwashing composition) preferably ranges from 10,000 cps to 5 million cps.The viscosity can be measured by means of a glass capillary viscometeras set out further in Dow Corning Corporate Test Method CTM004 Jul. 20,1970.

Suitable silicones include polydiorganosiloxanes, in particularpolydimethylsiloxanes which have the CTFA designation dimethicone. Anexample is dimethicone fluid having a viscosity of up to 100,000centistokes at 25° C., which is available commercially from the GeneralElectric Company as the Viscasil series and from Dow Corning as the DC200 series.

Aminofunctional silicones which have the CTFA designationamodimethicone, are also suitable for use in the compositions of theinvention, as are polydimethyl siloxanes having hydroxyl end groups,which have the CTFA designation dimethiconol.

Also suitable are silicone gums. “Silicone gum” denotespolydiorganosiloxanes having a molecular weight of from 200,000 to1,000,000 g/mol and specific examples include dimethicone gums,dimethiconol gums, polydimethyl siloxane/diphenyl/methylvinylsiloxanecopolymers, polydimethylsiloxane/methylvinylsiloxane copolymers andmixtures thereof. Examples include those materials described in U.S.Pat. No. 4,152,416 (Spitzer), and on General Electric Silicone Rubberproduct Data Sheet SE 30, SE 33, SE 54 and SE 76.

Also suitable for use in the present invention are silicone gums havinga slight degree of cross-linking, as are described for example in WO96/31188. These materials can impart body, volume and stylability tohair, as well as good wet and dry conditioning.

Preferred emulsified silicones for use in compositions of the inventionhave an average silicone particle size in the composition of less than100, preferably less than 30, more preferably less than 20 microns, mostpreferably less than 10 microns.

Particle size may be measured by means of a laser light scatteringtechnique, using a 2600D Particle Sizer from Malvern Instruments.

Suitable silicone emulsions for use in the invention are commerciallyavailable in a pre-emulsified form. This is particularly preferred sincethe pre-formed emulsion can be incorporated into the washing compositionby simple mixing.

Examples of suitable pre-formed emulsions include emulsions DC2-1766 andDC2-1784, available from Dow Corning. These are emulsions ofdimethiconol. Cross-linked silicone gums are also available in apre-emulsified form, which is advantageous for ease of formulation. Apreferred example is the material available from Dow Corning as DCX2-1787, which is an emulsion of cross-linked dimethiconol gum.

The amount of silicone incorporated into the compositions of theinvention depends on the level of conditioning desired and the materialused. A preferred amount is from 0.01 to about 10% by weight of thetotal composition although these limits are not absolute. The lowerlimit is determined by the minimum level to achieve conditioning and theupper limit by the maximum level to avoid making the hair and/or skinunacceptably greasy. We have found that an amount of silicone of from0.5 to 1.5% by weight of the total composition, is a particularlysuitable level.

A further preferred class of conditioning agents are per-alk(en)ylhydrocarbon materials, used to enhance the body, volume and stylabilityof hair.

EP 567 326 and EP 498 119 describe suitable peralk(en)yl hydrocarbonmaterials for imparting stylability and enhanced body to hair. Preferredmaterials are polyisobutylene materials available from Presperse, Inc.under the PERMETHYL trade name.

The amount of per-alk(en)yl hydrocarbon material incorporated into thecompositions of the invention depends on the level of body and volumeenhancement desired and the specific material used. A preferred amountis from 0.01 to about 10% by weight of the total composition althoughthese limits are not absolute. The lower limit is determined by theminimum level to achieve the body and volume enhancing effect and theupper limit by the maximum level to avoid making the hair unacceptablystiff. We have found that an amount of per-alk(en)yl hydrocarbonmaterial of from 0.5 to 2% by weight of the total composition is aparticularly suitable level.

When the hydrocarbon material is lipophilic, it may constitute all orpart of the lipophilic agent of the invention.

Compositions useful in the present invention may also be formulated astransparent or opaque emulsions, lotions, creams, pastes or gelsaccording to any of the methods known to the person skilled in the art.

In an alternative embodiment of the present invention, the compositionis a lotion or cream for direct application to the scalp.

Compositions of this invention may contain any other ingredient normallyused in hair treatment formulations. These other ingredients may includeviscosity modifiers, preservatives, colouring agents, polyols such asglycerine and polypropylene glycol, chelating agents such as EDTA,antioxidants, fragrances, and sunscreens. Each of these ingredients willbe present in an amount effective to accomplish its purpose. Generallythese optional ingredients are included individually at a level of up toabout 5% by weight of the total composition.

Preferably, compositions of this invention also contain adjuvantssuitable for hair care. Generally such ingredients are includedindividually at a level of up to 2%, preferably up to 1%, by weight ofthe total composition.

Among suitable hair care adjuvants, are:

(i) natural hair root nutrients, such as amino acids and sugars.Examples of suitable amino acids include arginine, cysteine, glutamine,glutamic acid, isoleucine, leucine, methionine, serine and valine,and/or precursors and derivatives thereof. The amino acids may be addedsingly, in mixtures, or in the form of peptides, e.g. di- andtripeptides. The amino acids may also be added in the form of a proteinhydrolysate, such as a keratin or collagen hydrolysate. Suitable sugarsare glucose, dextrose and fructose. These may be added singly or in theform of, e.g. fruit extracts. A particularly preferred combination ofnatural hair root nutrients for inclusion in compositions of theinvention is isoleucine and glucose. A particularly preferred amino acidnutrient is arginine.

(ii) hair fibre benefit agents. Examples are:

ceramides, for moisturising the fibre and maintaining cuticle integrity.Ceramides are available by extraction from natural sources, or assynthetic ceramides and pseudoceramides. A preferred ceramide isCeramide II, ex Quest. Mixtures of ceramides may also be suitable, suchas Ceramides LS, ex Laboratoires Serobiologiques. The ceramides mayconstitute all or part of the lipophilic agent of the invention.

Where the compositions of the invention are formulated as aqueouscompositions, water is typically present in an amount of 50% to 95% byweight, more preferably from 60% to 90% by weight, more preferably from70% to 90% by weight. Water is generally present as solvent and makes upthe balance of the weight of the composition. Other solvents, such asmono- or di-hydric alcohols having from 2 to 6 carbon atoms (eg, ethanoland propylene glycol) may optionally be used as cosolvents together withwater. Such cosolvents, if present, are generally present in an amountof from 0.1% to 5% by weight of the composition.

The compositions of the invention may be packaged in any suitable mannersuch as in a jar, a bottle, a tube, a roll-ball, or the like, in theconventional manner.

The method of the invention may be carried out from once or twice dailyto once weekly to the area of the scalp that requires treatment. Theimprovement in the appearance and/or feel of the scalp will usuallyappear after one to six weeks, depending on the condition of the scalp,the concentration of the active ingredients used in the method, theamount of the composition used and the frequency with which it isapplied.

In general, a quantity of the composition, for example, from 0.1 to 10ml is applied to the scalp from a suitable container or applicator andspread over and/or rubbed into the skin using the hands or fingers or asuitable device. A rinsing step may follow depending on whether thecomposition is formulated as a “leave on” or a “rinse-off” product.

The system of the invention for treating dandruff (which can also betermed a kit of parts) comprises: a first component comprising ananti-dandruff agent; and a second component comprising conjugatedlinoleic acid (CLA). The first component and the second component areboth suitable for, and are preferably adapted for, topical applicationto the scalp. The first component and the second component areformulated differently (for example, one component may be a lotion andthe other a shampoo, or one component may be a shampoo and the other aconditioner). The first component and the second component are appliedto the scalp in the desired order depending on their respectiveformulations (which may be formulated as described above in connectionwith the compositions of the invention), and the terms first and secondhave no significance in this regard i.e., the second component may beapplied to the scalp before the first component or vice versa. The firstcomponent and the second component are in separate compartments withinthe system, for example the system may comprise the first and secondcomponents packaged separately and further packaged such that the systemis sold as a single item or the first component and the second componentmay be in discrete compartments in a two-part package.

The invention will now be further illustrated by the following,non-limiting examples. In the examples and throughout the specificationall percentages are by weight based on the total-weight of thecomposition, unless indicated otherwise.

EXAMPLES Example 1

The following is an example of an anti-dandruff shampoo compositioncomprising conjugated linoleic acid in accordance with the presentinvention. Level (%) Level as 100% Activity recvd Trade name Chemicalname by wt. (%) (%) Conjugated Conjugated 2.00 100.00 100 Linoleic acidlinoleic acid Texapon N 70 SLES 2EO (70%) 16.00 70.00 22.86 (Henkel)Shanghai) CAPB - 30 Coco-amido propyl 2.00 30.00 6.66 (SH Goodway)betaine (30%) Jaguar C-17 Galactomannan 2- 0.20 100.00 0.20 (Rhodia)hydroxy- propyltrimethyl- ammonium chloride ether Zinc Omadine FPS Zincpyrithione, 1.00 48.00 2.08 (Yoshitomi) fine Polydimethoxy SiliconeDC1785 2.00 50.00 4.00 siloxane emulsion (Dow Corning) ETD980 ETD9800.60 100.00 0.60 (B F Goodrich) Formalin (37%) Formaldehyde 0.04 37.000.10 (SH Solvent Factory) Citric Acid Citric Acid 0.10 100.00 0.10 (SHGuansheng Yuan Bio-engineer Co.) Salt (SH Salt Co.) Sodium Chloride 0.40100.00 0.40 Sodium Hydroxide Sodium 0.30 100.00 0.30 (SH Dongfeng)Hydroxide Perfume, colour, <0.10 minors Dem. Water To 100.00 To 100.00100.00

Example 2 Demonstrating the Anti-Itch Effects of Conjugated LinoleicAcid in Combination with an Anti-Dandruff Shampoo

Composition A

This composition is used for comparison in the following protocol. LevelActivity, Level as (%) 100% Trade Name Chemical name Supplier % recvd, %by wt. Glydant plus DMDM hydantoin, etc Lonza 100 0.2 0.2 Tween 20POE(20) sorbitan mono laurate ICI 100 1 1 Carbopol 980 Poly acrylic acidGoodrich 100 2.5 2.5 Sodium Hydroxide Sodium Hydroxide SH Dongfeng 1000.1 0.1 Natrosol 250 HHR Natrosol Hydroxyethyl cellulose Aqualon 100 0.30.3 EDTA-2Na Disodium Ethylene diamine tetracetic acid Xiangde 100 0.050.05 Water Water Local 100 to 100% to 100%

Composition B includes the same components as composition A but inaddition contains conjugated linoleic acid in an amount of 3.0% byweight. Composition B is also used in the following protocol.

Compositions C and D Level (%) Level as by 100% Activity recvd Tradename Chemical name wt. (%) (%) Texapon N 70 SLES 2EO (70%) 16.00 70.0022.86 (Henkel Shanghai) CAPB - 30 Coco-amido propyl 2.00 30.00 6.66 (SHGoodway) betaine (30%) Jaguar C-17 Galactomannan 2- 0.20 100.00 0.20(Rhodia) hydroxypropyltri- methylammonium chloride ether Zinc OmadineFPS Zinc pyrithione, XX (Yoshitomi) fine Polydimethoxy Silicone DC17852.00 50.00 4.00 siloxane emulsion (Dow Corning) ETD980 ETD980 0.60100.00 0.60 (B F Goodrich) Formalin (37%) Formaldehyde 0.04 37.00 0.10(SH Solvent Factory) Citric Acid Citric Acid 0.10 100.00 0.10 (SHGuansheng Yuan Bio-engineer Co.) Salt Sodium Chloride 0.40 100.00 0.40(SH Salt Co.) Sodium Hydroxide Sodium Hydroxide 0.30 100.00 0.30 (SHDongfeng) Perfume, colour, <0.10 minors Dem. Water To 100.00 100.00 To100.00Composition C: XX = 0%Composition D: XX = 1% by wt.

Composition C is a non anti-dandruff (NAD) shampoo composition used forcomparison in the following protocol.

Composition D is an anti-dandruff (AD) shampoo composition used in thefollowing protocol.

Protocol

The effect of conjugated linoleic acid, used in conjunction withanti-dandruff (AD) and non anti-dandruff (NAD) shampoo, was clinicallyassessed using the following protocol.

The conjugated linoleic acid is used as a lotion (composition B). Thelotion base comprises Tween™ 20, Carbopol™ 980, Sodium Hydroxide,Natrosol™ 250HHR, EDTA-2Na, glydant plus and water (composition A). Theuse of the lotion is followed by a shampoo wash with an NAD shampoo(composition C) or an AD shampoo (composition D).

A randomised monadic double blind study design was used based on a totalof 240 screened panellists, male and female, with self-perceiveddandruff. All 240 panellists used a placebo shampoo (composition C) intheir normal hair wash routine for 4 successive weeks.

The panellists were divided into four groups (total number ofpanellists=240):

Group 1: 60 panellists. All panellists wash their hair with NAD shampooat home 3 times a week and apply CLA lotion one hour prior to washingtheir hair.

Group 2: 60 panellists. All panellists wash their hair with NAD shampooat home 3 times a week and apply lotion base (composition A) one hourprior to washing their hair.

Group 3: 60 panellists. All panellists wash their hair with AD shampooat home 3 times a week and apply CLA lotion one hour prior to washingtheir hair.

Group 4: 60 panellists. All panellists wash their hair with AD shampooat home 3 times a week and apply lotion base (composition A) one hourprior to washing their hair.

After their fourth visit, the panellists are instructed not to applylotion i.e., either base lotion (composition A), or CLA containinglotion (composition B) to their scalp prior to washing with shampoo forthe remainder of the study. Panellists come to the study centre at thesame frequency as before i.e., once a week for the next five successiveweeks for scalp assessments and continue hair washing at home as beforebut without using any lotion.

In order to assess the degree of itching at each visit to the studycentre, subjects are interviewed by an investigator about their itchfeeling on:

-   1) Itch degree-   2) Itch lasting time-   3) Itch frequency

According to the subject's response, the investigator will give a valuefrom the standard scale for the degree of itch feeling. The standardscale is as follows: 0 = None 1 = Mild 2 = Moderate 3 = Marked 4 =Severe

Analysis of itch scores is carried out using analysis of variance totest for main effects and interactions of NAD and AD shampoo and CLAcontaining lotion. The following individual comparisons are made testingfor significant differences at the 5% level. Data transforms ornon-parametric methods are used where necessary.

-   1) Non AD shampoo+CLA lotion vs Non AD shampoo+base lotion-   2) AD shampoo+CLA lotion vs AD shampoo+base lotion-   3) AD shampoo+CLA lotion vs Non AD shampoo+CLA lotion

The results from the above anti-itch study are summarised in FIG. 1.

FIG. 1 shows the results of the anti-itch study from the panellists ingroup 1 (NAD/CLA), group 2 (NAD/base), group 3 (AD/CLA) and group 4(AD/Base) in graphical form with itch degree on the vertical axis andthe week number of the protocol on the horizontal axis.

In FIG. 1, the graph shows that throughout the anti-itch study, thecombination of anti-dandruff (AD) shampoo and conjugated linoleic acidlotion (CLA), as used by the panellists in group 3, unexpectedly lowersthe degree of itch of the scalp compared to the compositions used in theother groups.

The results from group 3 are particularly surprising in view of theresults from group 2 and group 1. Thus, the results from group 1 showthat when CLA is used in combination with an NAD shampoo (NAD/CLA), thedegree of itch is actually higher than when an NAD shampoo is used incombination with the base composition (composition A) as in group 2.This comparison shows that CLA can increase the degree of scalp itch.

The results from group 4 show that when an AD shampoo is combined withthe base composition, the degree of itch can be lowered. When CLA iscombined with an anti-dandruff shampoo, as in group 3, the degree ofitch is significantly lowered. This would not have been expected fromthe results of group 1, which suggest that the addition of CLA shouldactually increase the degree of itch.

Therefore the results shown graphically in FIG. 1 indicate that there isan unexpected synergistic effect obtained from using the combination ofanti-dandruff agent and conjugated linoleic acid.

1. A composition for topical application to the scalp comprising (i) ananti-dandruff agent; (ii) conjugated linoleic acid; and (iii) acosmetically acceptable diluent or carrier, wherein the anti-dandruffagent is selected from metal pyrithiones, climbazole, ketoconazole andoctopirox.
 2. A composition as claimed in claim 1, which is a shampoo.3. A composition as claimed in claim 1, which is a lotion or cream fordirect application to the scalp.
 4. A composition as claimed in claim 1,wherein the anti-dandruff agent is zinc pyrithione.
 5. A composition asclaimed in claim 1, wherein the anti-dandruff agent is present in anamount of from 0.1% to 5% by weight.
 6. A composition as claimed inclaim 1, wherein the conjugated linoleic acid is present in an amount offrom 0.001% to 5% by weight.
 7. A system for treating dandruffcomprising: a first component comprising an anti-dandruff agent selectedfrom metal pyrithiones, climbazole, ketoconazole and octopirox; and asecond component comprising conjugated linoleic acid, wherein said firstcomponent and said second component are for topical application to thescalp and are in separate compartments within said system.
 8. A methodof treating and/or preventing dandruff which comprises applying to thescalp a composition of claim
 1. 9. The use of a synergistic combinationof an anti-dandruff agent and conjugated linoleic acid in themanufacture of a composition for treating and/or preventing dandruff,wherein the anti-dandruff agent is selected from metal pyrithiones,climbazole, ketoconazole and octopirox.
 10. A method of treating and/orpreventing scalp itch which comprises applying to the scalp acomposition of claim
 1. 11. The use of a synergistic combination of ananti-dandruff agent and conjugated linoleic acid in the manufacture of acomposition for treating and/or preventing scalp itch, wherein theanti-dandruff agent is selected from metal pyrithiones, climbazole,ketoconazole and octopirox.